1. Field of the Invention
The present invention relates to a technology for managing log data of a computer.
2. Description of the Related Art
When a failure occurs in a computer system, log data showing a usage status of the system is typically used for analyzing the cause and recovering the system. The log data is stored, in an order the log data is acquired, into a system disk. When the system disk is filled to the edge with the log data, the log data is overwritten and deleted in an order starting with the oldest data.
For example, Japanese Patent Application Laid-Open No. 03-105434 discloses a technology for providing a storage area dedicated for storing log data related to a failure. When a failure occurs in a system, log data showing the usage status before the system failed is immediately saved in the storage area. When the storage area is full, the log data is overwritten and deleted in an order starting with the oldest data.
However, because old data is overwritten and deleted when the storage area is full, the log data related to the failure might not be properly saved.
Moreover, some types of log data are used for analyzing the cause of a failure, while others are used for recovering the system. For example, when a contradiction between a command and a processing is detected while the computer is operating, and the computer is rebooted for data protection, log data required for analyzing the cause of the failure might be acquired after the failure. Thus, if log data acquired before the system failed is immediately saved as in Japanese Patent Application Laid-Open No. 03-105434, the log data related to the cause of the failure might not be properly saved.